Saw chains of the kind described above are known in various configurations and are disclosed, for example, in U.S. Pat. Nos. 3,292,670; 3,478,787; and, 4,434,556. The center links of these saw chains have respective foot portions with which they engage in the guide groove of the guide bar and thereby come into contact with the lubricant which is introduced periodically into the guide groove through a feed bore in the groove wall. As the saw chain moves around the guide bar, the lubricant can enter the lubricant channels which open into the guide groove at the forward edges of the foot portions with these edges being viewed as the forward edges with respect to the direction of advance of the saw chain as it moves around the guide bar.
U.S. Pat. No. 3,292,670 discloses such a guide channel in each of the center links. The guide channel extends toward the rearward rivet bore of the center link where it opens with the rearward bore being rearward with respect to the advancing direction of the saw chain in its movement around the guide bar. The lubrication of the saw chains links is not complete in this saw chain because only one of the two rivet bores arranged one behind the other receives lubricant directly.
Another saw chain is disclosed in U.S. Pat. No. 3,478,787 wherein two lubricant channels are provided for each center link and these two channels lead to respective ones of the two rivet bores. However, the opening of the forward lubricant channel is at a considerable distance away from the bottom of the guide groove so that this channel and therefore the forward rivet bore are not supplied with the lubricant continuously and in adequate quantities.
A further saw chain is disclosed in U.S. Pat. No. 4,434,556 wherein the lubricant supply at both rivet bores of the center links is improved in that the lubricant channel is branched to both rivet bores. However, the oil quantity taken up from the guide groove is often inadequate for providing a sufficient supply of lubricant to the rivet bores because the lubricant channel cannot take up enough lubricating oil especially because only the region close to the feed bore is available for this purpose.